In his book Morris argues that “the main function of war in cultural evolution across the past 15,000 years—and particularly across the past 500 years—has been to integrate societies, increasing material wellbeing.” It was war, strangely enough, that made our societies larger, wealthier, and safer. It must be understood that the argument here is “over the long run.” It goes without saying that wars created, and continue to create an enormous amount of human misery. But warfare creates an environment in which only societies that are strongly cooperative manage to persist and expand at the expense of less cooperative ones. Without war (or more broadly, without competition between societies) cooperation would unravel and disappear. Thus, wars have not only a destructive side, but also a creative one.

Wars that created empires created monopolies of power (to varying extents) over large areas. If those monopolies of power created trading areas with competing traders and a legal system that provided some protection for property rights then a really big benefit started to accumulate: selection for genetic variants that raised intelligence and increased time horizons for decision making. During the Malthusian Trap era such conditions selected for brighter people who were more cooperative and who applied lower discount rates in their brains when weighing future effects of decisions. Gregory Clark describes how this played out in England his book A Farewell to Alms: A Brief Economic History of the World.

Today, of course, the selective pressures have reversed. Can we shift back toward selection for more civilized and intelligent people without reentering the Malthusian Trap?

This is a very interesting and important subject. But it is also a chicken and egg question: Are the rising ruling elites created by the war aftermath of wars, or do the wars actually get triggered and implemented by the rising elites for the purpose of attaining their goals? No matter how surprising the escalation caused by the Sarajevo assassination was, in reality it was also clear that England and Germany were already preparing for a big war for many years: The British and German elites, to be more exact.

This probably depends on the destructive effects of wars. Perhaps wars in the past did not usually have as much destructive impact as modern wars. In wars like the two world wars the destruction and loss of lives is so immense that the overall effects are probably negative even for most of the victors.

Britain and France were "victors" in the First Woeld War but both emerged weaker than they were before the start of the war.

The most successful wars in history in terms of military victory and territory gained were the Mongol Conquests. But Mongolia today is of minor significance.

World War II certainly benefited the United States. We ended the war clear victors, with half the economic production on the planet, the most powerful military in the world, and a cohesive culture that had been mostly united in support of the war and with 15 million in uniform, did a remarkable job of pushing assimilation. The Gulf War, brief as it was, was also beneficial. We had put together a massive international coalition and demonstrated to the entire world the superiority of the US military and it's equipment. I can't say we've gotten much out of our other wars however.

I suspect war is probably one of the main drivers of human evolution in the past several thousand years. There have been hundreds of significant wars in Europe during that time and thousands of smaller spats. Generally speaking, the more advanced group should win and likely displace the less advanced group.

The British Empire owed no small debt to the wars which saw the original British islanders get the butts kicked by the Angle and Saxon groups.

An interesting argument, probably largely correct. Wars have killed lots of people, both military abd civilian, destroyed vast amounts of property and consumed enormous resources, but we all know that. However, some pretty productive societies have resulted. The Roman empire comes to mind. Its creation and maintenance were bloody in the extreme, but the society that resulted was the best in the word at that time, and we still enjoy some of its benefits. This probably never would have happened if the constituent parts had remained a bunch of warring city-states.

In the 19th and 20th centuries, the British empire comes to mind. Its creation wasn't exactly peaceful, but those who lived within it enjoyed peace, prosperity, rule of law, and scientific and cultural advancement. Of course, if you didn't behave, bad things tended to happen to you (ask the sepoys in India or the Zulus in Africa about that). In the 20th century, Britain got sucked into two world wars and, although technically victorious in both, was so depleted that the empire came apart.

The US participated in WW I and was victorious, suffering little damage in the process. However, the US experienced no benefit from the war. The decade of the 1920's was prosperous, but the Great Depression in the 1930's produced great suffering and bitter division (of course, the Depression was worldwide). As war clouds gathered in Europe, the American population was divided into those who favored support for the struggling democracies and those who opposed such support (the "Isolationists"). Pearl Harbor and Hitler's declaration of war immediately changed all that - the country became united as it probably never has been, before or since. Countries also learned to cooperate with each other to support the common cause of victory. The US and Britain, skeptical of each other prior to the war, became close allies. They even worked things out with Stalin's USSR, although that one didn't last. Following victory, the US played a major role in rebuilding shattered Germany and Japan, turning these former enemies into allies.

Althous America's steadfast opposition to Communist expansionism produced victory in the Cold War, it's hard to see how the post-WW II shooting wars have produced much benefit. Harry Truman's inability to win or end the Korean war sank his Administration, and the Vietnam and Gulf wars have been bitterly divisive. Still, it's hard to argue with the point that societies that are more cooperative (both internally and externally) do better in war.

Mike Street Station - Nations can certainly benefit from war. The expansion of the Roman Empire was immensely successful. Rome was even able to largely eliminate taxes on Roman citizens and still pay all it's soldiers because of the enormous amount of loot acquired. But you can only pillage a city every now and then, not every day. After the conquest of Britain the defence and maintenance of the Roman Empire became increasingly burdensome.

Empires are most profitable in their early period. Sort of like Puerto Rico for the US. How can we get rid of it now? Probably nobody would take it.

Technologically, during wars governments desperately spend a lot of money on cutting edge R & D that is very expensive and speculative. The latter type of R & D rarely gets launched by private corporations because it is financially very risky and profits are unpredictable or too distant in the future. However, the defense R & D that the government finances, often involves the best and the brightest scientists and engineers, and ultimately this work gets used in the private sector, leading to major changes in the economy. For example, nuclear power reactors would not have been developed by the private sector without the government involvement that was purely military at the beginning, because this kind of science was simply too expensive to develop. Similarly, microchips were initially developed to miniaturize military hardware, but currently the entire economy depends on this kind of electronic circuitry. During World War II, the fear that a European neo-pagan cult of death was developing nuclear weapons, made it impossible for the US not to launch the Manhattan Project, and this later lead to a major source of energy that is still being developed and it might ultimately save the world from peak oil. Similarly, if a modern military threat of global proportions develops in this century, the free world will once again launch desperate R & D programs that would involve cutting edge science, and some of this science will be applied to industry after the war. On the other hand, the recent low intensity guerrilla warfare in the Middle East involved relatively low-tech R & D, even though we wasted well over $1 trillion (double that amount if we take into account the future cost of the medical care that the wounded and traumatized soldiers will need in the future). The kind of enemy that we faced in the Middle East was not comparable to the industrialized and scientific adversaries that Nazi Germany and the Soviet Union were, and so the defense R & D against the current form of Middle Eastern wars will not yield much future benefit to the economy. Only in surveillance electronics and software some obvious breakthroughs were made in order to catch terrorists, but this will be of limited use outside data mining which was already being developed for consumer analysis related economic activity before even 9/11. Thus, the moral of the story is that if we want military research to engender economically revolutionary benefits, we must find a new kind of apocalyptic and satanic enemy that would strike true terror in the heart of the free world.